1. Field of the Invention
Example embodiments relate to a semiconductor device and a method of manufacturing the semiconductor device. More particularly, example embodiments relate to a semiconductor device having excellent data retention characteristics, a method of manufacturing the semiconductor device, a DRAM device, and a method of manufacturing the DRAM device.
2. Description of the Related Art
As a semiconductor devices become more highly integrated, the gate lengths of MOS transistors in the semiconductor device are greatly decreased. Recently, for example, a three-dimensional recess cell array transistor has been used as the MOS transistor in the semiconductor device.
Due to the size reduction of the MOS transistor, gate induced drain leakage (GIDL) and junction leakage current in the transistor are also increased. Thus, data retention characteristics of the semiconductor device are deteriorated by leakages of electric charges stored in the semiconductor device.
For example, the leakage current may occur due to trap sites generated by damage or stress generated during manufacturing the semiconductor device.
Accordingly, to prevent the trap sites from being generated, it may be required to optimize processes of manufacturing the semiconductor device.
Especially, due to the leakage current in a DRAM device, data retention time may shorten greatly and a refresh cycle may lengthen. Therefore, to manufacture a DRAM device having excellent characteristics, a new structure and method capable of preventing damages are required.